This invention relates to a distribution system utilizing oil droplets dispersed in air for lubricating bearing surfaces as for example roller bearings, sliding surfaces, gears, slideways, chains or similar mechanisms. In particular it relates to a distributor system which is not dependent on gravity and reduces oil omissions into the atmosphere.
The prior art on lubrication systems is primarily concerned with conveying oil in the form of a mist and precipitating the oil from the mist near the bearing to be lubricated. Although oil mist lubricators reduce the amount of oil consumption there is a loss through the bearing seals to the atmosphere. Gothberg, et al, U.S. Pat. No. 2,959,249 places local constrictors so as to change the oil mist to a mixture of fluid oil and air by precipitation. A precipitating nipple is used so that the amounts of oil precipitated can be changed as required by the bearings. A substantially high flow of the oil mist is directed against a transverse stationary surface to accomplish precipitation.
White, U.S. Pat. No. 3,665,684 is concerned with reclassifying micro particles of oil from an oil mist to substantially eliminate air pollution by such particles by use of a vacuum tank and pump and filter unit.
Malone, U.S. Pat. No. 2,334,942 is basically concerned with generating a continuous flow of oil mist, preferable bubbling air or other gas through a body of the lubricant.
The surface tension of atomized microfine oil particles is larger than the attraction force of the oil particles, so that the microfine atomized oil is in a state which is comparable to a gaseous condition of aggregation. The microfine atomized oil is in that state when conducted from the central atomizing appliance to the different friction points and is recondensed in corresponding nozzles in a manner as to form the droplet oil liquid.
One drawback of this oil spray system is that it is not possible to bring the oil spray completely back to the drop-like state.
The remaining oil spray can thus cause an environmental pollution with environmental damages. Furthermore, atomized oil spray can be transported only at very small distances, since the microfine atomized aggregation condition of oil is maintained only as long as the streaming remains laminary. When the streaming becomes turbulent, the oil particles are propelled against each other to unite and form big oil drops. In such a state no distribution is possible and the oil flows back to the container tank. The necessary small streaming velocity should be smaller than the critical streaming velocity corresponding to the Reynold's number, which necessitates relatively important cross-sections of conduits.
In oil dispersed in a turbulent air stream, the action of gravity provokes accumulation of the major part of the lubricant at the lowest points of the distributing apparatus so that distribution becomes dependent on location, which, for example in the case of vehicles lubricating systems can have negative consequences. Distributing devices with movable parts have proven impractical. Separate air cyclones are likewise impractical since the viscosity of lubricants varies within very wide limits. Lubricants, because of their widely variable viscosities, are not compatible and the ratio between the air and the oil quantity varies depending on necessity. Location plays a corresponding part. Thus it is accepted practice in a lubricating system of a mixture of oil and air to add oil to the air stream in a quantity corresponding to the location of each separate friction point.
One object of the present invention is to provide a novel distributor system for oil-air lubrication free of oil mist and having improved efficiency.
Another object of this invention is to provide such a system which is essentially independent of gravity so as to be effective regardless of the spacial orientation of the distributor mechanism.
Further objects and advantages of this invention will be apparent from the description and claims which follow taken together with the appended drawings.